摘要
采用MBE制备了CdSe/CdZnSe 多量子阱结构.X射线衍射谱的最高阶次是7,在77K下PL光谱的线宽是4.2nm ,表明我们的样品具有较高的质量.在变密度激发的ps 时间分辨光谱中,随着激发密度的减小发光衰减时间减小,认为是由无辐射复合引起的.
CdSe/CdZnSe quantum wells were grown by molecular beam epitaxy.The highest order satellite peak of the sample is 7 from XRD spectra and exciton emission linewidth is about 4 8nm at 77K.It is shown that our samples are very good.The recombination dynamics of exciton in high quality CdSe/CdZnSe MQWs are investigated by means of time resolved photoluminescence spectra with different excitation power at 77K.When weaker excitation is used,radiative recombination decay time of the exciton is reduced as the excitation intensity is decreased.The results indicate that the dominant mechanism may be quenching of exciton emission by impurities and defects.
基金
国家自然科学基金
中国科学院激发态物理开放研究实验室和中山大学超快速激光光谱学国家重点实验室基金